Apparatus for providing contact heads on contact members

ABSTRACT

In a welding apparatus for welding contact beads on a strip of spring metal, the bead material is fed in the form of pellets to a receptacle on one of the welding electrodes. The electrode is mounted on a carrier by means of a pivoted arm. In a position of the carrier remote from the welding area, a single pellet is transferred from a conduit to the receptacle. The carrier then moves to the welding area, the pivoted arm is swung to bring the receptacle into engagement with a strip which is also engaged by another electrode, and the pellet in the receptacle is welded to the strip. Contact members for electric circuits are frequently to be provided with contact heads of highly conductive material; this is true, e.g., for spring metal contact members which have a rather poor electric conductivity themselves. This invention relates to mechanical feeding systems for feeding contact metal pellets to the contact member in welding apparatuses.

United States Patent Bihler [72] Inventor: Otto Bihler, Halblech-Fussen,Germany [73] Assignee: Otto Bihler KG, Halblech-Fussen,

Germany [22] Filed: Jan. 28, 1971 [21] Appl. No.: 110,441

[30] Foreign Application Priority Data Feb. 4, 1970 Germany ..P 20 05094.6

[52] US. Cl. ..219/103, 29/493, 219/79 [51] Int. Cl. ..B23k 9/02 [58]Field of Search ..219/103, 104, 107, 79, 80; 29/630, 493

[56] References Cited UNITED STATES PATENTS 3,488,841 l/l970 Stern..219/104 X 3,194,940 7/1965 Thomson et a1. ..219/79 X 2,578,074 12/1951Kershaw ..219/103 2,154,243 4/1939 Langhaus ..2l9/lO3 [451 Sept. 26,1972 Attorney-Kelman & Berman [57] ABSTRACT In a welding apparatus forwelding contact beads on a strip of spring metal, the bead material isfed in the form of pellets to a receptacle on one of the weldingelectrodes. The electrode is mounted on a carrier by means of a pivotedarm. In a position of the carrier remote from the welding area, a singlepellet is transferred from a conduit to the receptacle. The carrier thenmoves to the welding area, the pivoted arm is swung to bring thereceptacle into engagement with a strip which is also engaged by anotherelectrode, and the pellet in the receptacle is welded to the strip.

8 Claims, 8 Drawing Figures JIL 2B a l PATENTED SEP 26 I972 sum 1 m 4INVENTOR Z1 l k, p I

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INVENTOR PATENTEnstPzslsn SHEET 3 OF 4 INVELN'TOR PATENTEDSEPZS 19123.694 6 l 4 sum u UF 4 I L VII] APPARATUS FOR PROVIDING CONTACT HEADS,ON CONTACT MEMBERS The primary object of this invention is theprovision of mechanical feeding means in a welding apparatus for feedingcontact metal pellets in welding position with respect to thecontactmember clamped in the welding apparatus. V

The problem of positioning the contact metal pellet with respect to thecontact member is different depending on the direction of the face ofthe contact member to which the contact head is to be welded.

A further object of this invention is to provide feeding means forfeeding the contact metal pellet into welding position when the pelletis to be welded to an upwardly directed face.

A further object of this invention is to' provide means forfeeding thecontact metal pellet into welding position when the pellet is to bewelded to a downwardly directed face.

Other features, additional objects, and many of the attendant advantagesof this invention will readily become apparent from the followingdescription of preferred embodiments when considered in connection withthe drawings, in which:

FIG. 1 shows an elevational section through a first embodiment of theapparatusaccording to the invention,

FIG. 2 is a section along the line II II of FIG. I,

. F IG. 3 is a fragmentary section corresponding to that of FIG. 1 andshowing the apparatus in another operating position,

FIG. 4 is a section along the line I'V IV of FIG. 3,

. FIG. 5 shows an elevational section corresponding to that of FIG. 1 ofa second .embodiment of an apparatus according to this invention,

. FIG. 6 is a section along the line VI VI of FIG. 5,

F IG 7 shows an elevational section of the apparatus of FIG. 5 inanother operating position, and

FIGQ8 is a section along'line VIII VIII of FIG. 7.

In the embodiment according to FIGS. 1 to 4 a metal tape 10 is shownwhich is continuously advanced at right angles to the drawing plane' ofFIG. I and is secured in processing position by clamping tools (notshown). Contact metal heads or heads 12 are to be mountedon the upwardlydirected face 14 of the metal tape 10; an electrode rod 16 is shownwhich is movable upwardly and downwardly in the direction of thedouble-arrow 18 so that itmay be approached for the welding process tothe lower side of the metal tape 10 while said tape is in clampedposition which prevents the tape from moving vertically. The apparatusfurthermore comprises a worktable 20 which is stationary relative to theclamping tools not shown. A movable feeding device 22 is mounted on saidworktable 20 and is longitudinally displaceable by means of a carrier orcarriage 26 along a guide 24 in the drawing plane. A mounting or swivelarm 28 is pivotally mounted at 30 on the carriage 26. This swivel arm 30carries adjacent the free end thereof a contact metal receptacle orreceiving pit 32 which is part of a positive counter electrode 34. Theswivel arm 28 is secured in an upper end position by a spiral tensionspring 35 and may be pivoted downwardly by a pneumatic actuator 36.

As shown in FIG. 2 a supply line or feeding conduit 40, the axis ofwhich is indicated by an arrow 42, leads from a hopper 38 receivingcontact metal pellets to the contact metal receiving area 44. Thissupply line 40 makes a 90 turn at 46 belowthe contact metal receivingarea 44. A lifting piston or plunger 48 is arranged below this turn andis shown in FIG. 2 in its lowermost position. The distance between theupper end of the lifting piston 48 and the bottom face 50 of the swivelarm 28 in the terminal portion of the conduit 40 is not greater than 1.5d, wherein d equals the cross-section of the contact metal pellets.

The apparatus described heretofore operates as follows:

In FIG. 1 and 2 the contact metal receiving pit 32 is in the contactmetal receiving area 44. By a lifting movement of the piston 48, whichis movable upwardly and downwardly in the direction of the double-arrow52, the leading contact metal pellet 54 is lifted into the contact metalreceiving pit 32 while the bend of the conduit 40 is obstructed by thepiston 48. The lifted pellet is preformed at its bottom surface whichsubsequently will be the welding basis. The contact metal pellet is,e.g., flattened or otherwise prepared, e.g., by forming projections forthe subsequent welding step. This allows a shorter welding time sincethe deformation to be carried out during the welding process is less.The piston 48 is slightly withdrawn, but the upper end face stillsecures the contact metal pellet 54 within this contact metal receivingpit 32. Thereupon the carriage 26 is moved toward the positionof FIG. 3.The lifting piston 48 may then completely return to the position shownin FIG. 2 whereupon the next contact metal pellet 54in FIG. 2 may arriveat a point below the contact metal receiving pit 32, there being onlyspace for one pellet between the upper end face 56 of the liftingpiston'48 and the surface 50 of the swivel arm 28.

1 While carriage 26 moves from the position shown in FIG. 1 to theposition of FIG. 3, the contact metal pellet 54 is secured by thecontact metal receiving pit 32 on the one hand and guided by a groove 58in the worktable on the other hand so that the pellet cannot drop out ofthe'contact metal receiving pit 32. The orifice of the conduit 40 abovethe plunger or piston 48 is blocked by the bottom face 50 of themounting or swivel arm 28.

As shown in FIG. 3, the contact metal receivingpit 32 has reached thewelding area 60 and the welding process may begin. For this purpose theelectrode 16 is raised. The swivel am 28 is pressed downwardly by thepneumatic actuator 36 while the contact metal pellet 54 is deformed to ahead 12 as shown in FIG. 1. When the welding process is finished thepneumatic actuator 36 is disconnected whereupon the spiral tensionspring 35 lifts the swivel arm 28 so that the metal tape 10 may beadvanced and the carriage 26 with the swivel arm 28 may return to theposition shown in FIG. I and 2. FIG. 1 shows a worktable 66 of awire-bending machine 64 wherein the tape 10 may be processed by tools68.

In FIG. 5 to 8 corresponding parts are designated with the samereference numerals as shown in FIG. 1 to 4 multiplied by the number 100.

The embodiment according to FIG. 5 to 8 operates as follows:

In FIG. 5 the contact metal receiving pit 132 is in the contact metalreceiving area 144. In this figure a contact metal pellet 154 enters thecontact metal receiving pit 132. The carriage 126 is subsequently movedto the the electrode 116 approaches the tape 110 from above.

The welding current is subsequently switched on. The swivel arm 128 ispivoted upwardly by the pneumatic actuator 136 so that the head 112according to FIG. 5 is formed. After termination of the welding processthe pneumatic actuator 136 is again switched off so" that the tape 110may continue to move and the carriage 126 may return to the positionshown in FIG. 5.

Changes and modifications of the illustrated embodiments of theinvention willreadily suggest themselves to those skilled in the art,and it should be understood that the invention is not limited to theexamples chosen for the purpose of the disclosure.

What is claimed is:

1. A welding apparatus comprising, in combination:

a. means for holding a contact member in a welding area;

b. a first electrode movable toward and away from a position ofengagement with a contact member held in said area;

c. acarrier;

d. guide means for guiding said carrier in a path between a firstposition remote from said area and a second position adjacent said area;

e. a second electrode mounted on said carrier for movement therewith insaid path,

I. said second electrode being formed with a receptacle;

f. feeding means for feeding a pellet of contact metal to saidreceptacle while said carrier is in said first position thereof;

g. securing means for securing said pellet in said receptacle duringmovement of said carrier from said first position to said secondposition; and

h. actuating means for moving said second electrode on said carriertransversely of said path when said carrier is in said second positionthereof, and for thereby moving said receptacle and the pellet thereintoward said contact member.

2. An apparatus as set forth in claim 1, further comprising a mountingmember pivotally secured to said carrier, said actuating means pivotallymoving said mounting member on said carrier, said second electrode beingfastened to said mounting member for joint pivotal movement transverselyof said path.

3. An apparatus as set forth in claim 2, wherein said actuating meansinclude yieldably resilient means on said carrier biasing said mountingmember to pivot in one direction, and an actuator mounted on saidcarrier and operable for pivoting said mounting member in a directionopposite to said one direction against the restraint of said yieldablyresilient means, said receptacle moving toward said contact member whensaid mountin member ivotsi said 0 osite'directi n.

. An apparatus is set orth in aim 1, said feeding means including asource of said pellets, a conduit leading from said source to saidreceptacle in said first position of the carrier, and limiting means forlimiting transfer of pellets from said conduit to said receptacle to asingle pellet after each movement of said carrier into said firstposition thereof.

5. An apparatus as set forth in claim 4, further comprising blockingmeans for blocking discharge of pellets from said conduit while saidcarrier is remote from said first position.

6. An apparatus as set forth in claim 5, wherein said limiting meansinclude a substantially rectangular turn in said conduit remote fromsaid source, the terminal portion of said conduit extending from saidbend in a direction away from said source and being dimensioned toreceive a single pellet only, and a plunger mounted for movement intoand out of said terminal portion for transferring a pellet received insaid terminal portion into said receptacle in said first position of thecarrier while obstructing said bend to the movement of an additionalpellet into said terminal portion.

7. An apparatus as set forth in claim 6, wherein said terminal portionhas an orifice and said mounting arm has a face, said orifice-beingaligned with said receptacle in said first position of said carrier, andsaid face obstructing said orifice and constituting said blocking meanswhen said carrier is remote from said first position.

8. An apparatus as set forth in-claim 5, wherein said conduit has anorifice remote from said source and said mounting arm has a face, saidorifice being aligned with said receptacle in the first position of saidcarrier, and said face constituting said blocking means and obstructingsaid orifice while said carrier is remote from said first position.

1. A welding apparatus comprising, in combination: a. means for holdinga contact member in a welding area; b. a first electrode movable towardand away from a position of engagement with a contact member held insaid area; c. a carrier; d. guide means for guiding said carrier in apath between a first position remote from said area and a secondposition adjacent said area; e. a second electrode mounted on saidcarrier for movement therewith in said path,
 1. said second electrodebeing formed with a receptacle; f. feeding means for feeding a pellet ofcontact metal to said receptacle while said carrier is in said firstposition thereof; g. securing means for securing said pellet in saidreceptacle during movement of said carrier from said first position tosaid second position; and h. actuating means for moving said secondelectrode on said carrier transversely of said path when said carrier isin said second position thereof, and for thereby moving said receptacleand the pellet therein toward said contact member.
 2. An apparatus asset forth in claim 1, further comprising a mounting member pivotallysecured to said carrier, said actuating means pivotally moving saidmounting member on said carrier, said second electrode being fastened tosaid mounting member for joint pivotal movement transversely of saidpath.
 3. An apparatus as set forth in claim 2, wherein said actuatingmeans include yieldably resilient means on said carrier biasing saidmounting member to pivot in one direction, and an actuator mounted onsaid carrier and operable for pivoting said mounting member in adirection opposite to said one direction against the restraint of saidyieldably resilient means, said receptacle moving toward said contactmember when said mounting member pivots in said opposite direction. 4.An apparatus as set forth in claim 1, said feeding means including asource of said pellets, a conduit leading from said source to saidreceptacle in said first position of the carrier, and limiting means forlimiting transfer of pellets from said conduit to said receptacle to asingle pellet after each movement of said carrier into said firstposition thereof.
 5. An apparatus as set forth in claim 4, furthercomprising blocking means for blocking discharge of pellets from saidconduit while said carrier is remote from said first position.
 6. Anapparatus as set forth in claim 5, wherein said limiting means include asubstantially rectangular turn in said conduit remote from said sourCe,the terminal portion of said conduit extending from said bend in adirection away from said source and being dimensioned to receive asingle pellet only, and a plunger mounted for movement into and out ofsaid terminal portion for transferring a pellet received in saidterminal portion into said receptacle in said first position of thecarrier while obstructing said bend to the movement of an additionalpellet into said terminal portion.
 7. An apparatus as set forth in claim6, wherein said terminal portion has an orifice and said mounting armhas a face, said orifice being aligned with said receptacle in saidfirst position of said carrier, and said face obstructing said orificeand constituting said blocking means when said carrier is remote fromsaid first position.
 8. An apparatus as set forth in claim 5, whereinsaid conduit has an orifice remote from said source and said mountingarm has a face, said orifice being aligned with said receptacle in thefirst position of said carrier, and said face constituting said blockingmeans and obstructing said orifice while said carrier is remote fromsaid first position.